Less than a half a million African elephants live in the wild and more than 25,000 of those are poached every year. They are poached for their ivory even though African ivory collected after 1989 is generally illegal. One reason such robust poaching persists is that, until recently, there has been no way to determine when ivory was collected. Dr. Kevin Uno joins us to discuss his recent PNAS article detailing a test that closes this loophole. In the process, we discuss carbon, ecology, elephants, and conservation.